OPINION:
Aside from militant cyclists, racists, bullies and Roosters fans, the people who used to annoy me most profoundly were vegans.

Self-righteous, hectoring, humourless, spoilsports - I'd have crossed a crowded dinner table to avoid them, until the fateful day I became one myself.

Even saying the words "I'm a vegan" still sounds alien, while the sense of shame I feel for my past sneering at these gentle people endures.

I realise I was once the bully I despised, imposing my will upon creatures simply because evolution has gifted me a place at the top of the food chain. Even worse I would smirk while spooning the misery of other creatures into my mouth and disparage people's attempts to explain why it might be wrong.

Once the light goes on and you realise the food you so blithely eat actually causes massive, life-long, completely avoidable suffering to billions of animals, it's not an easy epiphany to un-think.

A supermarket never looks the same, butcher shops become very dark places. The perversity of using smiling anthropomorphised animals to advertise packages of their own body parts grows almost chilling.

You also realise most vegans aren't doing it for dietary or faddish reasons but out of compassion and a sense of fairness.

Many also love the taste of meat, eggs and cheese (I certainly do) but realise you can easily survive and thrive without contributing to the almost unfathomable pain and distress inflicted on animals by factory farming.

The enlargement of moral sympathy to include both genders, all races, most religions, the disabled, the poor - even animals and the environment might one day be judged the defining virtue of humans who lived in the 20th and 21st centuries.

Thirty years ago, you could beat a dog on the street and not have stirred a response. Now you'd draw an angry crowd.

Brin recognises at some point - probably sooner than we think - a person's choice to eat meat drenched in suffering rather than produced in a vat, will be judged in much the same way we do a person swanning around in a mink coat.

Until then, vegans will exist in a space similar to the one once occupied by slavery abolitionists. Gary Smith, who runs a website called The Thinking Vegan, shared a common experience among vegans writing: "When you share what you have learned with your friends and family members, who you deeply respect and love, they show indifference at best.

"You feel like you have come upon genocide everyone is trying to hide and ignore. And you can no longer participate and no longer keep quiet. And then you are painted as militant, extreme, judgmental."

I came across that quote courtesy of Australian artist Jo Frederiks, who in September will launch an exhibition of her stunning and confronting paintings titled Animal Holocaust.

Frederiks, who grew up on a million-acre cattle farm and, as a youth, helped her dad brand, castrate and export tens of thousands of beasts for slaughter recently had her paintings removed from Facebook after users complained they were "offensive".

I guess they're the same people who'd say vat-grown meat is "disgusting" or "gross", yet are happy to consume the dead flesh of brutalised animals that live in their own excrement and misery.